Window-lifting mechanism.



- L. J. BERG.

WINDOW LIPTING MEGHANISM.

APPLICATION FILED DBO. 26, 1908.

Patented A'g. 24, 1909.

/y v mf 5.'

.UNrTnn sfrAfrns PATENT ornrcn.

LABS J. BERG, OF CHICAGO, ILLINOIS, ASSIGNOR TO METALLIC SHEATHING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

WINDOW-LIFTING MECHANISM.

To all whom it `m ay concern:

Be it ltnoivn that I, Lans J. BERG, a citizen oi the United States, residing at Chicago, in the county oil Cook and State oi' Illinois, have invented certain non.'Y and use'lul Improvements in WlindoW-Lil'ting Mechanism, of which the following is a specification.

This invention relates to spring mechanism lor controlling the movements ol a Window which is adapted to be used in lieu of Weights 1which are frequently employed for that purpose.

Under certain conditions, especially Where compactness of arrangement is desirable, as for instance in car windows, it is not desirable to use Weights, and the mechanism ol' the present invention is constructed with special reference to the economy of space and compactness or' arrangement. In the use of spring devices l'or this purpose the spring Will naturally be subjected to the greatest tension when the Windoiv is completely lowered, and will thereafter be subjected to a constantly lessening tension as the Windovvis raised more and more, permittingr the spring to resume its normal position.

The object ol' the present invention is to equalize the tension of the spring at dill'erent points in the travel of the window, or, if anything, to increase the pull ol the spring as the Window is raised7 so as to eliminate the tendency l'or a Window to Work up under spring tension after it has been completely closed.

The invention consists in the 'features of construction and combination of parte hereinafter described and claimed.

In tne drawings, Figure 1 is a sectional elevation oi'l a Window casing, showing the upper portion of a Window frame 5 Fig. 2 a cross sectional detail of the same Fig. 3 a longitudinal sectional view of the spring cylinder and Worm drum, and Fig. 4 a sectional view, showing the method of securing the spring in position.

The invention is applied to a Window frame 5, provided with suitable guide'xvays 6 for regulating the movements of the Window 7. The Window has secured thereto chains or cables S, the upper ends of Which are carried around Worm drums 9 and 10, Which increase in diameter toward the center and are provided With spirally extending grooves 11 adapted to have the chains fastened thereunto. The Worm drums are connected by means of a tubular casing or cylinder 12,1ilre I Specicaton of Letters Patent.

Application filed December 26, 1908.

Patented Aug. 24, 1909.

Serial No. 469,196.

that ordinarily employed in connection With Window shade rollers, which cylinder or casing has xedly located therein a block 13 which receives the inner end .of a coil spring 111, the outer end of which is entered into the enlarged inner end of a pintle 18 Which serves as a bearing lor the drum.

The inner block 13 is iXedly held Within the cylinder or casing in any suitable manner, and the pintle is loosely mounted therein and held against rotation With the cylinder by means of a liey or tongue 1Q, which is held Within a socket 20 suitably positioned Within the Window casing. The arrangement is one Which permits the casing With the Worm drums fiXedly secured thereto to revolve around the pintles as a bearing, and as the Window descends the chains will revolve the Worm drums and the cylinder, and cause the spring to be revolved, and thereby increase the tension on the spring. As shown, the cylinder is provided with but a single spring and pintle, though, obviously, this construction could be duplicated at the other end of the cylinder. The ends of the chain are iixedly secured near the inner or enlarged ends of the Worm drums, and as the chain Winds up it Will Wind on a drum of constantly decreasing diameter.

In use, with the Window in its lowermost position, the spring tension will be at its maximum and the pull on the chains will be exerted from the Worm drums at the point of greatest diameter and least eiiciency. This causes the Weight of the Window to exert its greatest eiiect in counterbalancing the tension of the spring, with the result that the greatest spring tension will act against the pull of the Window Working at the point of greatest leverage. As the Window rises the leverage will decrease in unison with the decrease of the spring tension, so that these two forces Will tend to counterbalance one another at all points in the travel of the Window. If desired, the parts can be proportioned to reverse the ordinary tendency and cause the spring to act more strongly toward the end of the Window movement than at the beginning. The arrangement, moreover, is one Which prevents the coils of the chain or cable from overlapping one another, since the chain or cable Will follow trie spiral groove from end to end of the Worm drums.

In assembling the parts, it is desirable to hold the drum against revolution With respect to the pintle When the parte have been put under spring tension` In order to secure this result, registeringl holes 2l' ere provided in the pintle and drum7 respectively, into any one of which e pin 22 can be teinporerily inserted, to be thereafter Withdrawn when the device is put into motion.

What l claim es new :me desire te secure by Letters Patent is:

In e device of the class described, in coinbinetion with s Window, e cylinder' rotatably I mounted above the Window, and provided at l esclu. end with a tapered drum, e connection l et each side oi the Window secured to the l larger end of the drum and revoluble therewith, and e spring Within the cylinder adepted to be put under tension by the lowering of' the Window, substantially es described. LABS J. BERG. W'itnesses:

WALKER BANNING, SAMUEL W. BANNING. 

